1. Field of the Invention
The present invention relates to a positive-type photoresist composition, a photoresist laminate using the positive-type photoresist composition, a method for producing a photoresist pattern, and a method for producing a connecting terminal.
2. Related Art
Photofabrication is now the mainstream of a microfabrication technique. Photofabrication is a generic term describing the technology used for manufacturing a wide variety of precision components such as semiconductor packages. The manufacturing is carried out by applying a photoresist composition to the surface of a processing target to form a photoresist layer, patterning this photoresist layer using photolithographic techniques, and then conducting chemical etching, electrolytic etching, and/or electroforming based mainly on electroplating, using the patterned photoresist layer (photoresist pattern) as a mask.
In recent years, high density packaging technologies have progressed in semiconductor packages along with downsizing electronics devices, and the increase in package density has been developed on the basis of mounting multi-pin thin film in packages, miniaturizing of package size, two-dimensional packaging technologies in flip-tip systems or three-dimensional packaging technologies. In these types of high density packaging techniques, connection terminals, including protruding electrodes (mounting terminals) known as bumps that protrude above the package or metal posts that extend from peripheral terminals on the wafer and connect rewiring with the mounting terminals, are disposed on the surface of the substrate with high precision.
In the photofabrication as described above, a photoresist composition is used, and chemically amplified photoresist compositions containing an acid generator have been known as such a photoresist composition, (see Patent Documents 1, 2 and the like). According to the chemically amplified photoresist composition, an acid is generated from the acid generator upon irradiation with radiation (exposure) and diffusion of the acid is promoted through heat treatment, to cause an acid catalytic reaction with a base resin and the like in the composition resulting in a change to the alkali-solubility of the same.
Such a chemically amplified positive-type photoresist composition is used for forming, for example, bumps or metal posts through plating processes. Specifically, a photoresist layer having a desired film thickness is formed on a support by using a chemically amplified photoresist composition, and the photoresist layer is exposed through a predetermined mask pattern and is developed. Thereby, a photoresist pattern in which portions for forming bumps or metal posts have been selectively removed (stripped) is formed. Then, bumps or metal posts can be formed by embedding a conductor such as copper into the removed portions (resist-free portions) using plating, and then removing the surrounding residual resist pattern.    Patent Document 1: Japanese Unexamined Patent Application, Publication No. H9-176112    Patent Document 2: Japanese Unexamined Patent Application, Publication No. H11-52562